Late on a recent morning, a woman slowly rode a bicycle beneath the trees along the sun-dappled shores of Sha Tau Kok, a small village on the Hong Kong-China border.

It was a rare moment of tranquility amid modern China’s bustling urban sprawl. But now this crescent of greenery is at the centre of increasingly fraught tensions between the former British Colony and president Xi Jinping’s Communist government in Beijing. 

Six years ago, mainland authorities occupied a small parcel of land in the village – reportedly for military use – after diverting the course of a river. 

Carrie Lam, chief executive of Hong Kong, initially said her administration was unaware of any such land occupation. 

But…